Elysia nealae Ostergaard, 1955

Location: Sokodo(Sanmata), Hachijo Island, Tokyo, Japan
Date: 2017/04/19
Length: 40mm
Depth: 8.0m
Water temperature: 14.7℃

Description

A slender sacoglossan reaching about 33 mm in length and 4 mm in width. Body slender and elongate, tapering posteriorly. Parapodial lobes intensely folded, the medially-directed folds meeting dorsally. Rhinophores slender, straight, tapering toward the extremities and directed antero-laterally. Eyes prominent, set at the postero-lateral bases of the rhinophores, each surrounded by a small white area. Foot slightly bilobed with a shallow median anterior notch, tapering posteriorly to an obtuse point. Body pale to bright green throughout, with small white specks and fine concentrated masses of green algal cells especially conspicuous on the parapodial lobes; margins of the parapodial lobes and the posterior tip greenish yellow. Feeds by suctorial grazing on green algae and retains chloroplasts in its tissues.

Distribution

Central Pacific. Type locality: Waikiki (near the Hawaii Marine Laboratory), Oahu, Hawaii, on seaweeds (24 November 1923, leg. Marie C. Neal; holotype USNM 574930). Also recorded from Japan (including the Ryukyu Islands), Guam, and Palmyra Atoll.

Etymology

The specific epithet nealae honours Marie Catherine Neal (1889-1965), the Hawaiian botanist who collected the type specimen on seaweeds at Waikiki.

Remarks

Distinguished from the sympatric Elysia degeneri by long, smooth, tapering rhinophores (those of E. degeneri are short, knobbed, and non-tapering) and by uniformly green parapodial lobes (those of E. degeneri are bordered medially with bright orange).